IMMUNOCYTOCHEMICAL DETECTION OF PROSTAGLANDIN-E(2) IN MICROVASCULATURE AND IN NEURONS OF RAT-BRAIN AFTER ADMINISTRATION OF BACTERIAL-ENDOTOXIN

The aim of the present study was to identify the site of prostaglandin E2 (PGE2) production in the brain in response to a pyrogenic dose of endotoxin. The presence of PGE2 was detected using immunocytochemistry on Bouin's fixed vibratome sections of control and endotoxin-treated rats. Peripheral administration of endotoxin caused a time-related sti mulation of PGE2 immunoreactivity (irPGE2) in the choroid plexus and i n the microvasculature of the brain. In addition to these sites, hypop hysiotrophic neurons of the paraventricular nucleus (PVN) and supraopt icus nucleus (SON) responded with induction of irPGE2 to endotoxin adm inistration. Our data demonstrate that alterations in brain function i n response to endotoxin may involve arachidonic metabolities such as P GE2 that are induced at the blood-brain barrier (microvasculature) and blood-liquour barrier (choroid plexus) and in hypohysiotrophic neuron s of the rat brain.